The Avalon Peninsula is a large peninsula (9,270 km²) that makes up the southeast portion of the island of Newfoundland.

The peninsula is home to forty percent of Newfoundland's population, and is the location of the capital, St. John's. It is connected to the main section of the island by the 5 km/3 mi-wide Isthmus of Avalon . The peninsula protrudes into the rich fishing zones near the Grand Banks. Its four major bays—Trinity Bay, Placentia Bay, St. Mary's Bay , and Conception Bay —have long been the centre of Newfoundland's fishing industry.

The peninsula was one of the first European inhabited areas in North America, with the first permanent settlement established at Cuper's Cove in 1610. Sir George Calvert was later given a large land holding on the peninsula. The initial colony of Ferryland grew to a population of 100 becoming the first successful permanent settlement on Newfoundland island. In 1623 Calvert was given a Royal Charter extending his lands and granting them the name Province of Avalon "in imitation of Old Avalon in Somersetshire wherein Glassenbury stands, the first fruits of Christianity in Britain as the other was in that party of America." Calvert wished to make the colony a refuge for Roman Catholics facing persecution in England. In 1625 Calvert was made the first Lord Baltimore in recognition of his achievements.

The charter created the province as a palatinate in which Calvert had absolute authority.

A series of crises and calamaties led Calvert to quit the colony in 1629 for "some other warmer climate of this new world" which turned out to be Maryland though his family was to maintain agents to govern Avalon until 1637 when the entire island of Newfoundland was granted by charter to Sir David Kirke and James Hamilton, 1st Duke of Hamilton.

Calvert's son, Cæcilius Calvert, 2nd Baron Baltimore, fought against the new charter and, in 1660, gained official recognition of the old Charter of Avalon but never attempted to retake the colony.

See also:

• British colonization of the Americas